Common year starting on Sunday

A common year starting on Sunday is any non-leap year (i.e. a year with 365 days) that begins on Sunday, 1 January, and ends on Sunday, 31 December. Its dominical letter hence is A. The current year, 2023, is a common year of this type. The last such year was 2017 and the next one will be 2034,^[1] or, likewise, 2018 and 2029 in the obsolete Julian calendar, see below for more. Any common year that starts on Sunday, Monday or Tuesday has two Friday the 13ths. This common year contains two Friday the 13ths in January and October.

Calendars[]

Calendar for any common year starting on Sunday,
presented as common in many English-speaking areas

ISO 8601-conformant calendar with week numbers for any common year starting on Sunday (dominical letter A)
Template:Calendar/isoMonthStartSun	Template:Calendar/isoMonthStartWed	Template:Calendar/isoMonthStartWed	Template:Calendar/isoMonthStartSat
Template:Calendar/isoMonthStartMon	Template:Calendar/isoMonthStartThu	Template:Calendar/isoMonthStartSat	Template:Calendar/isoMonthStartTue
Template:Calendar/isoMonthStartFri	Template:Calendar/isoMonthStartSun	Template:Calendar/isoMonthStartWed	Template:Calendar/isoMonthStartFri

Applicable years[]

Gregorian Calendar[]

In the (currently used) Gregorian calendar, alongside Monday, Wednesday, Friday or Saturday, the fourteen types of year (seven common, seven leap) repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Sunday. The 28-year sub-cycle does only span across century years divisible by 400, e.g. 1600, 2000, and 2400.

Gregorian common years starting on Sunday^[1]
Decade	1st	2nd		3rd	4th		5th		6th	7th		8th		9th	10th
16th century	prior to first adoption (proleptic)													1589	1595
17th century	1606	1617		1623	1634		1645		1651	1662		1673	1679	1690	—
18th century	1702	1713	1719	1730	—		1741	1747	1758	1769		1775		1786	1797
19th century	1809	1815		1826	1837		1843		1854	1865		1871		1882	1893	1899
20th century	1905	1911		1922	1933	1939	1950		—	1961	1967	1978		1989	1995
21st century	2006	2017		2023	2034		2045		2051	2062		2073	2079	2090	—
22nd century	2102	2113	2119	2130	—		2141	2147	2158	2169		2175		2186	2197

Julian Calendar[]

In the now-obsolete Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a 28-year cycle (1461 weeks). A leap year has two adjoining dominical letters (one for January and February and the other for March to December, as 29 February has no letter). This sequence occurs exactly once within a cycle, and every common letter thrice.

As the Julian calendar repeats after 28 years that means it will also repeat after 700 years, i.e. 25 cycles. The year's position in the cycle is given by the formula ((year + 8) mod 28) + 1). Years 11, 22 and 28 of the cycle are common years beginning on Sunday. 2017 is year 10 of the cycle. Approximately 10.71% of all years are common years beginning on Sunday.

Julian common years starting on Sunday
Decade	1st		2nd		3rd		4th		5th		6th		7th		8th		9th		10th
15th century	1402		1413	1419	1430		—		1441	1447	1458		1469		1475		1486		1497
16th century	1503		1514		1525		1531		1542		1553	1559	1570		—		1581	1587	1598
17th century	1609		1615		1626		1637		1643		1654		1665		1671		1682		1693	1699
18th century	1710		—		1721	1727	1738		1749		1755		1766		1777		1783		1794
19th century	1805		1811		1822		1833	1839	1850		—		1861	1867	1878		1889		1895
20th century	1906		1917		1923		1934		1945		1951		1962		1973	1979	1990		—
21st century	2001	2007	2018		2029		2035		2046		2057		2063		2074		2085		2091

References[]

Template:List of calendars

^ ^a ^b Robert van Gent (2017). "The Mathematics of the ISO 8601 Calendar". Utrecht University, Department of Mathematics. http://www.staff.science.uu.nl/~gent0113/calendar/isocalendar.htm. Retrieved 20 July 2017.

This page uses content from the English language Wikipedia. The original content was at Common year starting on Sunday. The list of authors can be seen in the page history. As with this Familypedia wiki, the content of Wikipedia is available under the Creative Commons License.

[math-1] Robert van Gent (2017). "The Mathematics of the ISO 8601 Calendar". Utrecht University, Department of Mathematics. http://www.staff.science.uu.nl/~gent0113/calendar/isocalendar.htm. Retrieved 20 July 2017.

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